In general, the present invention relates to a wiper blade and a method of manufacturing the wiper blade and more particularly, to a wiper blade superior in wiping the surface of a transparent material, for example, glass treated with water-repellent agent and a method of manufacturing the wiper blade.
The wiper blade for a vehicle, train, and the like swings in sliding contact with the surface of a windowpane thereof to allow a driver to secure the visual field. Therefore, it is necessary for the wiper blade to have a high degree of flexibility and restoring property; a high degree of durability such as water-proofness, weatherability, and wear resistance; not to judder on the windowpane; and have a high wiping performance.
In order to comply with such demands, a rubber material which is halogenated to harden the surface thereof so that the wiper blade slides easily on the windowpane and has a high degree of wear resistance is widely used as wiper blades. In addition, the following wiper blades are known: Binder mixed with molybdenum disulfide or graphite is applied to the surface of wiper blade, as disclosed in Laid-Open Japanese Patent Publication No. 55-113545; and a film made of polyvinylidene fluoride, polyvinyl chloride or polyurethane is formed on the surface of wiper blade, as disclosed in Laid-Open Japanese Patent Publication No. 5-97015.
Further, there is disclosed, in Laid-Open Japanese Patent Publication No. 8-48800, a resinous coating material made of rubber or plastic containing solid lubricant as well as silicone rubber and having a low coefficient of friction and a high degree of resistance to wear.
However, the wiper blade comprising the halogenated rubber does not slide on a glass surface sufficiently. In particular, the wiper blade does not slide well on a glass surface to which wax or the like has attached and further, judders when it slides thereon in contact therewith. Thus, the wiper blade has an unfavorable wiping performance. If the rubber is halogenated in a high extent, the surface of the wiper blade is likely to be cracked and marks are left on the glass surface by the sliding contact of the wiper blade with the glass surface.
The wiper blade coated with the binder disclosed in Laid-Open Japanese Patent Publication No. 55-113545 does not judder when it slides on the glass surface in contact therewith and has a superior wiping performance only in a short period of time after the coating is applied to the surface of the wiper blade. But with a long-time use, the coating peels off from the surface of the wiper blade and thus the wiper blade judders when it slides on the glass surface in contact therewith. Thus, the wiper blade deteriorates in its wiping performance with age.
Each of the wiper blades coated with the film disclosed in Laid-Open Japanese Patent Publication Nos. 5-97015 and 8-48800 has a favorable wiping performance on a clean glass surface but judders on a glass surface to which wax, dust or sand has attached and a water-repellent glass surface, thus having an unfavorable wiping performance.
As described above, the conventional wiper blade is inferior in durability and wiping performance and in particular, incapable of wiping the water-repellent glass surface favorably.